Lawmakers from both parties said they were disappointed, but said that silence from the two executives would not stop them from pursuing their investigation into a $528 million loan that Solyndra Inc. received from the Energy Department in 2009.

The panel's chairman, Rep. Fred Upton, R-Mich., compared the Solyndra loan to the Great Train Robbery in England in the 1960s.

"It appears we have a great heist of over half a billion dollars and ... maybe even co-conspirators called the U.S. government," Upton said.

Upton faulted the Obama administration for its role in the loan, saying at a minimum the Energy Department did not complete due diligence on the company, which lost hundreds of millions of dollars in the years before the loan was approved.

He called the loan "reckless use of taxpayer dollars on a company that was known to pose serious risks before a single dime went out the door."

Meanwhile, fallout from the Solyndra controversy continued. A solar company slated to get a separate Energy Department loan guarantee said Friday it has been told the guarantee will not be approved in time to meet a federal deadline.

The Energy Department said earlier this month it would provide a partial guarantee for a $344 million loan to San Mateo, Calif.-based SolarCity to install solar panels on 160,000 homes across 124 military bases in 33 states.

But SolarCity said in a letter to Congress Friday that the project now appears to be dead. "In the past 48 hours, DOE has informed us ... they will be unable to finalize the loan guarantee" by Sept. 30, the company said in a letter to Upton and other committee leaders. "The reason provided was the increased documentation requirements that are the result of the current congressional investigation into the Solyndra bankruptcy."

SolarCity CEO Lyndon Rive called his company a victim of Solyndra, and urged Congress to extend the Sept. 30 deadline by a few weeks to allow his project and others to move forward. DOE has said as many as 14 projects worth a total of nearly $9 billion face the Sept. 30 deadline.

"It's a shame to pull the plug on this project just because of the Solyndra bankruptcy," Rive said.

An Energy Department official confirmed that the SolarCity project would not close by Sept. 30, but would not say the reason.

Spokesman Damien LaVera said in an email that the department has consistently said it will not close any deal until rigorous technical, legal and financial reviews have been completed.

"Failure to close a loan application does not indicate that a project doesn't have merit or a strong business case to succeed, but rather that all of the extensive due diligence and legal documentation simply cannot be completed by September 30," LaVera said.

The Energy Department has requested additional funding for the loan program in the budget year that begins Oct. 1. "If Congress provides those funds, additional projects can be considered based upon the availability of that funding," LaVera said.

Rep. Cory Gardner, R-Colo., said it was important for the committee's investigation of Solyndra to continue.

GOP lawmakers said they were expanding their inquiry into the Solyndra loan, which has become a rallying point for Republican critics of the administration's push for so-called green jobs.

Lawmakers said they want the administration to turn over all communications between the Energy Department and White House related to Solyndra, as well as all communications between Energy and the Treasury, which lent Solyndra the money.

Committee leaders said the administration may have violated the law when it restructured Solyndra's loan in February in such a way that private investors moved ahead of taxpayers for repayment in case of default. The economic stimulus law provides for taxpayers to be ahead of other creditors in the event of bankruptcy or default.

Deputy Energy Secretary Daniel Poneman said Thursday that the restructuring was "entirely legal," noting that another aspect of the law requires Energy Secretary Steven Chu and other officials to protect the overall interests of taxpayers. Poneman said the restructuring accomplished that because it gave the struggling company a better chance to succeed.

Solyndra filed for Chapter 11 bankruptcy protection earlier this month and laid off its 1,100 employees.

The Fremont, Calif.-based company was the first renewable-energy company to receive a loan guarantee under a stimulus-law program to encourage green energy and was frequently touted by the Obama administration as a model. President Barack Obama visited the company's Silicon Valley headquarters last year, and Vice President Joe Biden spoke by satellite at its groundbreaking ceremony.

Since then, the company's implosion and revelations that the administration hurried Office of Management and Budget officials to finish their review of the loan in time for the September 2009 groundbreaking has become an embarrassment for Obama as he tries to sell his new job-creation program.

Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Video: Solyndra execs invoke 5th amendment

Closed captioning of: Solyndra execs invoke 5th amendment

>>critical spotlight shining on top executives from the failed
solar energy
company that got hundreds of millions of dollars of taxpayer funded loans. just moments ago, sow lin dhra solyndra ceo, sworn in.

>>the important oversight role that it plays. as much as i wish to be able to answer the members' questions, i have been advised by my counsel it is the better course for me to assert my constitutional right to decline to answer questions under the fifth amendment.

>>now we have our own
modern day
great train robbery. but it appears we have a great heist of over half a billion dollars and possibly even willing collaborators maybe even co-conspirators of the
u.s. government
who rushed out a $535 million loan to solyndra.

>>kelly o'donnell is watching the hearing. kelly, listening to are the start of it, that's a sample. pretty fiery.

>> reporter: one of those times when members ever congress are pointing fingers, raising this voices targeting those two executives. in part, with just a week of going bankrupt those two gentlemen, harrison and stover came to
members of congress
and talked about the health of their company. there are members who feel they were lied toance and there's a bigger issue about the fate of
solar energy
and the programs associated with them, and that's where it falls on political lines. fregs, you' for example one of the more senior members, democrat markey, an expert on this. they were making an example of this one's company to hurt a broader industry.

>>the republican majority is recklessly exploiting this one case to advance a
political agenda
that is very clearly aimed at killing the
solar wind
and renewable industries.

>> reporter: one of the things we'll see is a lot of discussion about the 1,000 employees who lost their job, the loan, half billion dollars not repaid. so when the witnesses decide not to answer questions by taking their fifth amendment rights, and there were some members of the committee who said they respect that, but were angry they couldn't get their questions answered. then it becomes the sort of
political theater
of asking those questions anyway, and subjecting those two officials to kind of the withering experience at being before congress. there's an ongoing investigation. much more of this. this was certainly one of the timing you could see congress venting anger feeling duped by this company and the taxpayers as well. richard?